1. Field of the Invention
The present invention relates to vehicle top article carriers comprising a stationary frame structure rigidly secured to the top of a vehicle and a relatively movable loading and unloading article supporting rail structure (wherein which the loading and unloading rail) may be readily moved to an inclined loading position with one end resting upon the ground and the other end pivotally interconnected to the stationary frame structure. The loaded supporting rail structure may be then readily moved to a transit position with the stationary frame on the vehicle top.
2. Description of the Prior Art
As is well known in the art, the market place is replete with car top luggage and ski racks, and with many kinds of carriers which are able to carry small boats and other similar cargo.
Many of these carriers have a stable frame which is typically mounted on the top of the vehicle and at least two rails which move from a position atop the frame to a position at an end of the frame where the rails are pivoted to an inclined position so as to engage the ground. In this inclined position the rails are loaded and repositioned to the top of the frame. See for example, the U.S. Pat. Nos. 2,506,421 and 2,551,357 issued to F. H. Hacker et al and E. C. Swenson, respectively.
Some of these devices employ rollers to facilitate the travel of the rails relative to the frame. The patent to R. J. Essling for example, U.S. Pat. No. 3,193,124 shows a device which employs rollers in this manner.
A number of problems have become evident in these devices. One of the major problems is that many times there is no reliable mechanism to prevent the rails from totally disengaging from the frame while the loading operation is in progress. This causes many of these devices to be unsafe for the person loading the cargo and to raise a risk of possible cargo damage.
Also many of the prior devices were difficult to use inasmuch as the rails would not easily move from their position on top of the frame to the inclined position. This caused a significant problem in the routine use of any of these devices.
Therefore, an object of the present invention is to design an article carrier which is of simple, sturdy design onto which a boat, camping equipment or the like may be easily loaded and unloaded with great safety from any accidental disengagement of the rails during the loading operation.
Another object is to design a simple reliable system to facilitate the movement of the rails along the frame of the article carrier which will remain easy to operate for long periods of time.
A further object is to design an article carrier of a very simple practical design composed of few parts that can be readily manufactured and assembled.
A further object is to design an article carrier in which all moving parts are securely locked together during transit.
The above, as well as other objects and advantages of the present invention, may be achieved by an article carrier for a vehicle top having a pair of spaced apart channel members adapted to span the substantial width of a vehicle top with means to securee the channel members to the vehicle top; article supporting rails; arrays of rollers connected to each of the rails and adapted to be received within respective ones of the channel members to thereby provide for relative movement therebetween, each of the arrays including one roller of a larger diameter than the other rollers of the array; and detent means extending inwardly of each of the channel members to militate against the passage of the large supporting rail members having a larger diameter than the other rollers in the array, which are received by diameter roller of the array while permitting the passage of the other rollers of the arrays.